There are generally provided car carrier trucks is described above as shown in FIGS. 50 and 51.
Referring to FIGS. 50 and 51, reference numeral 11 indicates a chassis, and a dump frame 12 is provided on the chassis 11.
At the rear end of the dump frame 12, there is provided a hinge bracket 13. The hinge bracket 13 is pivotably connected to the chassis 11 through a hinge shaft 14. Furthermore, a tilt cylinder 16 is provided between the chassis 11 and the dump frame 12 so that the dump frame 12 is tilted by elongation of the tilt cylinder 16.
On the dump frame 12 is mounted a cargo container 17 for carrying vehicles. A slide cylinder 18 is longitudinally provided between the dump frame 12 and the cargo container 17. Elongation of the slide cylinder 18 slides the cargo container 17 backward.
When the cargo container is slid backward, cargo container support legs 19 for the cargo container reach the ground to support the cargo container 17.
Conventionally, in order to insure that the cargo container 17 smoothly slides on the dump frame 12 without being derailed therefrom, an upper part of the dump frame 12 is inserted, as shown in FIG. 52, between a sectionally U-shaped main girder 22 mounted on the bottom of the cargo container 17 in the longitudinal direction and a subsidiary girder 23 provided inside of the main girder 22. An upper sliding pad 24 and a lower sliding pad 25 are fastened respectively to the upper and lower surfaces of the upper part of the dump frame 12 with bolts so that the subsidiary girder 23 is slidably supported on the upper sliding pad 24 and a lower portion of the main girder 22 slidably rests on the lower sliding pad 25.
In the conventional pad mounting structure, the upper and lower sliding pads 24 and 25 are fastened to the dump frame 12 with bolts. However, because the bolt fastening work for the lower sliding pad 25 is done in a narrow space, the positioning of the bolt holes is difficult and therefore the mounting operation or the replacing operation of the lower sliding pad 25 is difficult, which is a problem.
Therefore, a first object of the present invention is to provide a sliding pad mounting structure of a car carrier truck in which the mounting and replacement of a lower sliding pad is easy.
Furthermore, the above-described conventional car carrier truck has the following problems. Namely, the vertical distance between the load-carrying platform and the dump frame increases by the diameter of the cylinder, and consequently, an increase in the height of the load-carrying platform, taking the form of a cargo container is inevitable. As a result, in tilting the dump frame backward and sliding the load-carrying platform backward to bring it into contact with the ground, the tilt angle becomes large, resulting in that the slope of the load-carrying platform becomes steep and therefore difficult for construction vehicles to go up.
Moreover, although the distance between the load-carrying platform and the dump frame can be shortened by notching a traverse girder at a portion where the cylinder device is located, this causes a problem of lowering the strength of the load-carrying platform.
Therefore, a second object of the present invention is, in a car carrier truck which has a load-carrying platform supported on a sufficiently strong dump frame such that the load-carrying platform can be slid back and forth by a cylinder device, to prevent the tilt angle of the load-carrying platform from being too large when the dump frame is tilted, by making the height of the load-carrying platform from the ground small.
Furthermore, in a car carrier truck which loads vehicles by sliding the cargo container backward, individual support legs are provided on the chassis and the cargo container in order to securely support the chassis and cargo container during the loading and unloading of vehicles. Because these support legs, particularly those provided on the chassis, are an obstacle to the running of the truck if extended, they are conventionally retracted by an operator during the driving.
However, such retraction work has to be performed by going below the cargo container, and thus hard work is forced upon the worker.
Therefore, a third object of the present invention is to effect an automatic extension and retraction of the chassis support legs with the sliding operation of the cargo container, thus eliminating the need for an operator to go below the cargo container and enabling the extension and retraction to be safely and securely performed.
Furthermore, a fourth object of the present invention is to prevent the failure of springs biasing the chassis-supporting legs by prohibiting the springs, even though the load-carrying platform is fully tilted, from being elongated more than the spring elongation when the chassis supporting legs are retracted.
A fifth object of the present invention is to securely fasten the cargo container to the dump frame during travel and also to automatically fasten the cargo container to the dump frame after the completion of loading or unloading of vehicles.
A sixth object of the present invention is to provide a car carrier truck used also as a dump truck which is capable of using a rear hinged door securely as a foot board without dropping the board off when loading or unloading of vehicles, and also capable of fastening the cargo container to the dump frame and securely dumping loaded items without the possibility of turning the truck over in the dumping operation.
A seventh object of the present invention is to secure a clearance between the cargo container and the chassis by providing a stopper member either on a lower surface of the cargo container or on an upper surface of the chassis in order to prevent piping passing through a space between front and rear wooden supports fastened onto the chassis from being damaged.
In the truck as shown in FIGS. 50 and 51, since the main girders 22 extending longitudinally on the bottom face of the cargo container 17 are in direct sliding contact with the dump frame 12, the back and forth movements of the cargo container 17 can not be effected smoothly because of a large sliding resistance. A clearance is provided between respective side surfaces of the dump frame 12 and the main girder 22 so that both side surfaces do not contact each other in order to reduce the sliding resistance. For this reason, rolling takes place during the back or forth movement of the cargo container. Particularly when the cargo container is moved backward, the portion of the main girder 22" supported by the dump frame 12 of the main girder 22 becomes shorter and the rolling becomes larger. There is then a danger that vehicles on the cargo container will slide down on the cargo container by their own weight.
Accordingly, an eighth object of the present invention is to enable smooth back and forth movements of the load-carrying platform with the aid of a moving pad provided on the cargo container, namely, on the load-carrying platform, and a fixed pad provided on the dump frame, and also to prevent rolling of the load-carrying platform at all times with the aid of the moving pad and a rear fixed pad.
Furthermore, there has been known a car carrier truck used also as a dump truck which has a locking device provided between a dump frame and a load-carrying platform. When the truck is used as a dump truck, the locking device is brought into a locking state such that the load-carrying platform is fully tilted integrally with the dump frame. When the truck is used as a car carrier truck, the locking device is brought into an unlocking state such that after the dump frame is tilted by a predetermined angle, the load-carrying platform is moved back and forth for loading or unloading vehicles.
However, in such an arrangement, the locking device must be changed over to the locking or unlocking state in accordance with each job. Particularly when the truck is used as a dump truck, if a full tip is effected without changing over the locking device to the locking state, there is a danger that the load-carrying platform will drop from the dump frame and hurt a worker.
Therefore, a ninth object of the present invention is to provide a car carrier truck used also as a dump truck wherein the locking device is provided with a lock detection device, and a full-tipping operation is allowed only when a locking state of the locking device is detected by the lock detection device.
A tenth object of the present invention is to provide a car carrier truck used also as a dump truck wherein when the tilt of the load-carrying platform is below a predetermined lower limit, back and forth movements of the load-carrying platform are restrained, and when a predetermined upper limit is reached, the load-carrying platform is not allowed to be tilted more. Back and forth moving operation of the load-carrying platform within only a predetermined range of the tilt angle is thereby ensured.
An eleventh object of the present invention is to enable operations to be controlled from inside a cab when the dump and car carrier truck is used as a dump truck and, on the other hand, to enable operations to be controlled from outside the cab, with safety being confirmed, when the truck is used as a car carrier truck.